Expat Mortgage Calculator: UK Borrowing After Currency Cuts

Article updated 31 October 2026

The calculator above estimates what a UK lender could lend you while you live abroad. It cuts foreign currency income before applying an income multiple, checks the loan-to-value, and its buy-to-let tab sizes the loan on rent instead. Mortgage One is a whole of market mortgage adviser arranging UK residential and buy-to-let mortgages for British expats paid in foreign currency.

For a free initial consultation that runs your own figures through each lender's currency cut and country list, call 01202 155992 or contact Mortgage One.

How the expat mortgage calculator works out your borrowing

You enter foreign income already converted to pounds. The calculator removes the lender's currency cut, adds any sterling income in full and multiplies the total by the income multiple. On £100,000 of foreign pay with a 20% cut and 4.5 times income, it counts £80,000 and estimates £360,000 of borrowing.

It then compares that limit with the mortgage you need. On a £450,000 home with a £112,500 deposit, the £337,500 loan sits inside the £360,000 limit at exactly 75% loan-to-value, and at an illustrative 5.5% over 25 years it costs £2,073 a month. Lenders also check outgoings, credit and their own minimum income, which the tool cannot see. HSBC, for example, needs £75,000 of basic income on a non-UK resident application, so treat the result as the ceiling a lender starts from rather than an offer.

A partner's UK salary goes in the sterling box and counts in full, because no currency risk applies to it. The same household with a £40,000 UK salary alongside the £100,000 of foreign pay reaches £120,000 of counted income and an estimated £540,000. Where one of you lives in the UK and the other abroad, our guide to joint mortgages with a non-UK resident covers how lenders assess the pair.

What currency cut should you enter in the calculator?

Enter the cut published by the lender you expect to use, or leave the box blank to test at 20%. Darlington Building Society converts foreign income at the XE.com rate and then takes 20% off, so £100,000 counts as £80,000. Other lenders cut less, a few cut nothing, and some refuse certain currencies outright.

The cut covers exchange rate movement over the life of the loan, so it varies by lender and often by currency. Our expat mortgages guide lists the cuts at named lenders currency by currency. Running the calculator at 0%, 10% and 20% shows how far the choice of lender moves your borrowing before any other criteria apply: on £100,000 of foreign pay at 4.5 times income, each 10 points of cut is worth £45,000.

The income multiple moves too. Darlington lends up to 6 times income on its foreign currency range, against the 4.5 times the calculator starts from, but the highest multiples usually come with a minimum income or a lower loan-to-value. That is why the multiple box starts cautious, and why a higher figure in the box is not a promise that a lender will lend it to you.

Loan-to-value caps and the deposit the calculator tests

Most expat lenders cap lending at 75% loan-to-value, so a 25% deposit is the working assumption. HSBC caps non-UK resident lending at 75%, while Darlington's foreign currency range reaches 90% for borrowers who meet its rules. The calculator flags any case above 75%, where the list of lenders narrows sharply.

On a £450,000 purchase, 75% loan-to-value leaves a £112,500 deposit and 90% would leave £45,000. A buyer who has not been in the UK for 183 days in the 12 months before the purchase also pays a 2% stamp duty surcharge in England or Northern Ireland, £9,000 on that £450,000 home, which the calculator leaves out. Our stamp duty calculator adds the surcharge to the standard bands before you settle on a deposit.

Expat buy-to-let calculator: how rent cover sets the loan

The buy-to-let tab sizes the loan on rent, not salary. Lenders want the rent to cover the interest by 125% for a basic rate taxpayer or 145% for a higher rate taxpayer, tested at a stress rate of at least 5.5%. On £1,500 a month that supports £261,818 at 125% and £225,705 at 145%.

The tab then applies a 75% loan-to-value cap and uses whichever limit is lower. On a £350,000 flat let at £1,500 a month the two limits almost meet, at £261,818 and £262,500, so the deposit needed is £88,182. At £2,000 a month on a £400,000 property the rent would support £349,091, but the cap holds the loan at £300,000.

Some expat lenders test at a rate well above 5.5% on shorter fixes, so change the stress rate box to match the deal you are looking at. Our rental stress test calculator runs the same rent test for UK-resident landlords, and our table of current expat mortgage rates shows what the lenders charge at 75% loan-to-value.

If the rent cover or the loan-to-value cap is holding your expat buy-to-let back, call 01202 155992 or contact Mortgage One.

Which limit applies when the calculator figures disagree?

The lowest one. A lender lends the smallest of what your counted income supports, what its loan-to-value cap allows and, on buy-to-let, what the rent covers at its stress rate. The calculator shows each limit on its own line, so you can see which to work on: a bigger deposit, a smaller currency cut or a higher rent.

That is where the choice of lender does the work. Two lenders can look identical on rate and still lend £45,000 apart on the same salary because of the currency cut alone, and a lender that accepts your country and currency at 75% beats one that goes to 90% but not for where you live. A specialist expat mortgage broker matches those rules to your case before anything is submitted.

To have your figures run against the lenders that accept your country and currency, call 01202 155992 or contact Mortgage One.

Back to Calculators

The information provided in this article is for general guidance only and does not constitute personal or regulated financial advice. If you'd like to understand what these moves could mean for you, speak to Mortgage One. We can explain your options and timings based on your specific circumstances.

FAQs

1. How much can I borrow as an expat? It depends on the lender's currency cut and income multiple. On £100,000 of foreign pay with a 20% cut and 4.5 times income, the calculator estimates £360,000, and Darlington Building Society lends up to 6 times income on its foreign currency range, subject to its other criteria.

2. How much deposit do I need for an expat mortgage? Usually 25%, because most expat lenders cap lending at 75% loan-to-value, HSBC among them. A few building societies lend British expats up to 90% on a home, and expat buy-to-let lenders commonly stop at 75%.

3. Can I use foreign income for a UK mortgage? Yes, with lenders that accept your currency. They convert it to sterling and usually cut it before applying the income multiple, Darlington by 20%, so the calculator lets you set the cut to match the lender.

4. What rent do I need for an expat buy-to-let mortgage? Enough to cover the interest by 125% at a stress rate of at least 5.5%, or 145% for a higher rate taxpayer. £1,500 a month supports a loan of about £261,818 at 125%, and the buy-to-let tab works the sum backwards from your rent.

5. Does the calculator include stamp duty and fees? No. It covers borrowing and deposit only. Buyers who are not UK resident for stamp duty pay a 2% surcharge in England and Northern Ireland, and lender, valuation and legal fees come on top.

6. Should an expat use a mortgage broker? A broker matters more from abroad than at home, because country lists, currency cuts and income multiples differ between lenders, and the cheapest rate is often not the lender that lends most on your income. A whole of market adviser tests the case against each lender's rules before an application is made.